Rhizoctonia solani Kuhn, and Fusarium solani (Mart.) Apple & Wr. were the most frequently isolated fungi from diseased roots of pea plants (Pisum sativum L.). R. solani was more aggressive than F. solani in the pre-emergence damping-off phase. Littel Marvel cultivar was more sensitive to diseases infection than Perfection cv. Soil infestation with F. solani and R. solani reduced the number of Rhizobium leguminosarym nodules on pea roots, than the non-infested soil. Monceren was the most-effective fungicide increased root nodules number while, Benlate showed the lowest effect. Number of nodules formed on roots of Perfection cv. was more than that formed on Littel Marvel cv. in all treatments. The tested antagonistic fungi (Chaetomium globosum, Gtiocladium virens and Trichoderma harzianum) and their combinations showed an increasing effect on root nodules number. Treatment with Trichoderma harzianum + Gliocladium virens was the best combination in increasing root nodules number specially in case of Perfection cv. Addition of Rhizobium with biocontrol agents to the infected soil caused high reduction in the disease incidence. All combinations including T. harzianum gave better disease control in both pea cultivars. Combinations of Rhizobium with all antagonistic fungi caused high increase in all growth characters (i.e. plant length, as well as fresh and dry- weight) of tested pea cultivars. Soil infested with pea rhizobia only or in combination with fungicides increased crop parameters. The best combination in this respect was Benlate + Rhizobium in both pea tested cultivars. |
